AC Vector Drive

[sonics103]

We have an application where a variable frequency drive is used to power a Scott-T transformer. This product has used a 10 HP Volkman spindle drive for many years that can no longer be purchased. We were forced to switch to an "equivalent" AC Vector Drive and for some unknown reason; the performance is less than half of its former capability. Volkman, now Vacon, has turned OFF the vector calculations for us (we think so anyway) with some improvement but the machine is still way underperforming? The new drive produces higher voltage and current at the same frequency but does not deliver 10 HP? The only thing left is the phase of the currents? If the vector adjustments are OFF base for some reason so that the Scott-T is not doing its thing, maybe something out of phase could cause this type of result. If anyone has any thoughts on the subject we would be grateful for a few ideas. Thanks.

 

[waross]

A Scott connection transforms between 3 phase and 2 phase.
A "T" connection transforms between 3 phase and 3 phase.
Both transformers use a center tapped transformer and a transformer with a tap that is not centered.
The tap positions on the second transformers are not the same position.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[waross]

Higher voltage? Are you saturating your transformer?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[burnt2x]

sonics103,
Maybe you mean a ferroresonant converter? Pls try to look at the attached file.